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2 years ago

Determine the speed of a falling object 7.8 sec after it dropped.

Physics

1 answer:

butalik [34]2 years ago

7 0

Answer:

76.4m/s

Explanation:

Given parameter:

Time taken = 7.8sec

Unknown:

Speed after it dropped = ?

Solution:

To solve this problem, we use one of the kinematics equation:

V = U + gt

V is the final speed

U is the initial speed = 0m/s

g is the acceleration due to gravity

t is the time taken

V = 0 + 9.8 x 7.8 = 76.4m/s

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A hot metal bolt of mass 0.06 kg and specific heat capacity 899 J/kg°C is dropped into a calorimeter containing 0.16 kg water at

skad [1K]

Answer:

Explanation:

Given

mass of hot metal $m_1=0.06\ kg$

specific heat $c=889\ J/kg-^{\circ}C$

mass of water $m_2=0.16\ kg$

Temperature pf water $T_2=20^{\circ}C$

Final Temperature $T=25^{\circ}C$

let $T_1$ be the temperature of hot metal ball

Heat lost by heat metal bolt is gained by water in calorimeter

Heat lost by hot metal bolt $Q_1=m\times c\times \Delta T$

$Q_1=0.06\times 889\times (T-25)$

Heat gained by water $Q_2=m_2\times c_w\times \Delta T$

$Q_2=0.16\times 4184\times (25-20)$

$Q_1=Q_2$

$0.06\times 889\times (T-25)=0.16\times 4184\times (25-20)$

$T_1=25+62.75$

$T_1=87.75^{\circ}C$

7 0

2 years ago

A crane lifts a 100 kg concrete block to a vertical height of 25 m. Calculate

Nana76 [90]

Answer:

Solon,

total mass (kg)= 100kg

height (h)= 25m

acceleration due to gravity = 9.8m/s²

so,

work done =m*g*h

= 100*9.8*25

= 24,500 joule

5 0

2 years ago

An atom that changes so that it has an<br> electrical charge is a(n)

MrMuchimi

Answer:

An ion.

Explanation:

Atoms can gain or lose electrons and become ions, which are atoms that have a positive or negative charge, because they have unequal numbers of protons and electrons.

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2 years ago

3. A 5 gm/100 ml solution of drug X is stored in a closed test tube

JulijaS [17]

Answer:

See explanation

Explanation:

The degradation of the drug is a first order process;

Hence;

ln[A] = ln[A]o - kt

Where;

ln[A] = final concentration of the drug

ln[A]o= initial concentration of the drug = 5 gm/100

k= degradation constant = 0.05 day-1

t= time taken

When [A] =[ A]o - 0.5[A]o = 0.5[A]o

ln2.5 = ln5 - 0.05t

ln2.5- ln5 = - 0.05t

t= ln2.5- ln5/-0.05

t= 0.9162 - 1.6094/-0.05

t= 14 days

b) when [A] = [A]o - 0.9[A]o = 0.1[A]o

ln0.5 = ln5 -0.05t

t= ln0.5 - ln5/0.05

t= -0.693 - 1.6094/-0.05

t= 46 days

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2 years ago

As the bright sun shines upon the water, the water slowly disappears. The same sunlight gives energy to the surrounding plans to

mariarad [96]

first is physical .... sec chem

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3 years ago